Coated fabrics and processes of making same



Patented Aug. 15, 1950 COATED'FABRIGS AND PROCESSES OF MAKING SAME Allan S. Richardson, J r., SouthQQrt, Gnn., as-

signor to E. I. du rem de Nemours hCqmpany Wilmington, DeL, a corporation. of Dela ware No Drawing. Application April 24, 1948, Serial-No. 23,135

9 Claims. 1

This invention relates to fabrics having-a coat.- ing thereon and. more particularly to'a method of improying the bond between the coating and: the fabric substrate.

Heretofore, fabrios have been coated with, a variety of filmy-forming agents. More recently, many new synthetic resinous materials have been proposed. for fabric coatings McQueen patent,

2,212,785, described. aprocessior the preparatifin of .chlorosuiionated, olefin polymers, such as the chlorosulfonation products of normally sol-id. polymers of ethylene or isohutylene. In copenciing application Serial/No. 65 L822, filed, March 3.5, 19.45, hy Richard E.. Brooks. et at, there is clescrihed new and novel. compositions, for adhering chlorosulfonatedethylene polymer compositions to other surfaces. It has/been discovered that still further improvem nts. in bonding sis/2h coinpositions to flexible fabrics, can be realized. in aocorciance with the invention-described heretoafter.

The primary object of this; invention is to pro? vide new and novel compositions adhere tenaoiously to flexible substrates. A. further ob.- ject is to, provide improved cositic-ns as. an intermediate :bonding medium or flexible sub! strates and chlorcsulfonated ethylene polymercompositions. These and. other important :objects will be readily apparent as the descriptionof the invention proceeds.

The objects of this inventi n are accomplished by preparing a dispersion, in a volatile organic solvent, comprising chlorosulfonatecl ethylene polymer and. a polymeric lower alkyl :ester of acrylic or methacrylic acid, applying it to flexible substrate, and then heating to evaporate the'solvent. The alkylester is one having the'foll'owing formula:

EXAMPLES I TO v Five compositions represented by Examp e I :0

V, in- Which= the-formu1ae are indicatedas parts;

Weight, were prepared:

Base coating compositions Example I II Ill. IV V Chlorosullonatedethylene polymer 100 100 l0(l l00 190 Polymeric methyl metlmcrylnt'e 0 Hydtoquinone mono benzyl-etherl 1 1 l 1 Wood rosin 4 4 4 4 4' Magnesium oiriow 12- 12 12 12 12' e 4e 4': '4- l 4, 4

K 4 lugs-gent) l l- 1 1 l ompos ons becam appa ntly l 'l l ee s .1 .i

ey w e ved r m he ein i the form oi hic absan th bro en r ut ntosma l p ec s xam e. wa hin ed. w th oluene to ve a. p eari i s sco i y. About. 1x 0 ba e-:1 o ta omposi ion o t uolrlus mil e oron it on) s re u ed? os e. a s re din scos tr.

coa s. f. each omposit on. re re en ed W Examples. 1 to V we e ppli d on sep ate la e of a 53" woven cotton sateen fabric running 1.12

Calender coimposz'tzbn Chlorosulf onated ethylene p )l3 m 1 er 1 ),Q,0 Hydroouinone mono benzyl ether 1,0 lf ed il 2 ,10. Wood rosin u n 10.0 Polyoxyethylene glycol 3.0 Fine particle size precipitated calcium carbonate 80.0

lored pismentsr 122 The above ingredients were thoroughly masticated. on va two roll rubbermill until homogeneous and were then taken from the rolls in the form of slabs, and stored for further processing. During th m ing al rati n, the t mperature of th mposition rose to approximately 200 F. due to internal friction of the mass. After storing, the following materials were added to the slabs on a two roll rubber mill:

Parts by weight Magnesium oxide l2 Litharge 4 Benzothiazyl disulfide 1 After the above ingredients were milled with the slabs, the mass was heated up to approximately 200 F. to form a plastic mass, which was transferred to heated calender rolls, where it was calendered onto the above-described base coated fabrics. Approximately ten ounces per square yard were applied in one application to each of the above-described base coated fabrics.

The calender coating compositions released from the rolls of the two roll mixing mill and the calender rolls without any tendency to adhere to the heated rolls. The polyoxyethylene glycol employed in the above formula is a translucent Waxy solid having an average molecular weight of 3000 to 3700, and contributed to the good release of the calender composition from the heated metal rolls.

The above-described coated fabrics may be processed further by graining or embossing, which is accomplished by passing the coated fabric between heated pressure rolls, one of which has a design engraved on the surface. Heated pressure plates may also be employed for the embossing operation. The coated fabrics may be further decorated if desired by applying a dilute toluene dispersion of a composition similar to the calender coating composition containing pigments of contrasting color or lustre. The finishing composition is deposited in the valleys of depressed areas of the embossed design and wiped off the raised portion. As a final manufacturing operation, the coated fabrics were subjected to a temperature of 260 F. for two hours to cure or vulcanize both the base coating composition and the calender coating composition as well as any finishing composition that may be employed.

The samples containing the different base coats as represented by Examples I to V, were tested after the final heat treatment for mechanical scrub resistance and anchorage of coating to the fabric. The results were as follows:

Control Example I II III IV I V Parts of methyl methacrylate polymer to 100 parts of chlorosulfonated ethylene p ymer Adhesion of coating to fabric (1" strip) lbs 3. 4 4. 0 5.6 4. 2 4. 2 Mechanical scrub resistance 3, 100 6, 000 10, 000 6. 000 5,000

4 U. S. Patent 1,980,483, issued November 13, 1934 to Hill or by any other known method.

The following examples illustrate embodiments of the invention using combinations of chlorosulfonated ethylene polymer with higher polymeric esters of methacrylic acid. Alkyl esters having up to 8 carbon atoms; 1. e., octyl methacrylate make satisfactory coatings for fabrics. Corresponding esters of acrylic acid may be used and substituted in l1ke amount for the methacrylate esters in the examples.

Example VI VII VIII IX Chlorosulfonated Ethylene polymer .l 100 100 100 50/50 n-butyl/isobutyl methacrylate interpolym 1 Polyethylmethacrylate... 25 Polybutyl methacrylate 25 Polyisobutylmethaerylate 25 Benzothiazol Disulfida l l l 1 Wood rosin 4 4 4 4 Extra Light Magnesium Oxide. l2 l2 l2 l2 Litliarge 4 4 4 4 Retainer W (Salicylic Acid plus a dispersing agent) l 1 1 l Toluene 343 343 343 343 All the ingredients of each example save the wood rosin, the polymethacrylic acid ester, and toluene were milled together on a two roll rubber mill. The wood rosin and polymethacrylic acid esters were dissolved in a portion of the toluene and the milled mixture and the balance of the toluene were blended with the solution of wood rosin and the polymethacrylic acid ester to form the base coating composition.

Each composition was spread on separate pieces of textile fabric in the same manner as that described above for Examples I to IV.

The base coated fabrics were then further coated with the calender composition described above in a manner similar to that employed in Examples I to V. After the calender coating operation, the samples were finished in the same manner described above for Examples I to V, except the curing operation was carried out at 280 F. for two hours.

Samples containing the different base coats referred to as Examples VI to IX were then tested for anchorage of the coating to the fabric and mechanical scrub resistance. The results were as In the above examples the ratio of polymeric esters of acrylic and methacrylic acids to chlorosulfonated ethylene polymer varies between 20 parts and 40 parts of polymeric methyl methacrylate to each 100 parts of chlorosulfonated ethylene polymer. The preferred ratio is 25 parts of polymeric esters of acrylic or methacrylic acids to 100 parts of chlorosulfonated ethylene polymer.

The preferred embodiment of this invention employs a textile fabric with a base coat comprising polymeric esters of acrylic or methacrylic acids and chlorosulfonated ethylene polymer dispersed in a volatile organic solvent and a second coating of chlorosulfonated ethylene polymer containing no polymeric ester described above superposed over the base coating composition. It is within the scope of this invention to prepare fabrics with improved adhesion of the coating to the fabric and resistance to mechanical scrubbing, in which the entire coating consists of a blend of chlorosulfonated ethylene polymer and polymeric esters of acrylic or methacrylic acids within the range set forth above.

The polymeric esters described above cannot be completely dispersed with other coating ingredients on a two roll rubber mill, and where they are employed with the chlorosulfonated ethylene polymer, it is necessary to prepare a dispersion of the pre-milled ingredients in a volatile organic solvent and then apply a plurality of coats of the coating composition to the surface to be coated by conventional means, such as, e. g., doctor knife, roller, etc. It will be readily apparent to those skilled in the art that the secondary compounding ingredients such as pigments, fillers, accelerators, curing agents, etc. can be varied over a relatively wide range.

The advantages of the coated fabrics produced in accordance with the present invention are the increased adhesion of the coating to the cotton textile fabric and resistance to mechanical scrub.

It is apparent that many widely different embodiments of this invention may be made without departing from the spirit and scope thereof, and therefore, it is not intended to be limited except as indicated in the appended claims.

I claim:

1. A textile fabric base coated with a composition comprising 100 parts of chlorosulfonated ethylene polymer and from 20 to 40 parts of polymeric ester having the formula where Y is an alkyl group of 8 carbon atoms or less and X is an H or CH: group, and a second coatin superposed thereover consisting of chlorosulfonated ethylene polymer as the filmforming agent.

2. The product of claim 1 which contains 25 parts of polymeric ester for each 100 parts of chlorosulfonated ethylene polymer.

3. A textile fabric coated with a composition comprising 100 parts of chlorosulfonated ethylene polymer and from 20 to 40 parts of polymeric methyl methacrylate.

4. The product of claim 3 which contains 25 parts of polymeric methyl methacrylate for each 100 parts of chlorosulfonated ethylene polymer.

5. The product of claim 1 in which the polymeric ester is one of methacrylic acid.

6. The process of coating a textile fabric which comprises preparing a composition comprising an intimate mixture of 100 parts of chlorosulfonated ethylene polymer and 20 to parts of polymeric methyl methacrylate, dispersing said mixture in a volatile solvent, applying said composition on a textile fabric heating to evaporate the solvent and further heating to cure the said coating.

7. The process of claim 6 which contains 25 parts of polymeric methyl methacrylate for each parts of chlorosulfonated ethylene polymer.

8. The process of coating a textile fabric which comprises preparing a composition comprising a co -dispersion of 100 parts of chlorosulfonated ethylene polymer and 20 to 40 parts of polymeric methyl methacrylate, applying said composition to the textile fabric, heating to evaporate the solvent, preparing a second coating composition comprising chlorosulfonated ethylene polymer and other compounding ingredients without polymeric methyl methacrylate, applying said second coating over said first coating and heating at an elevated temperature sufficient to cure said coatings.

9. The product of claim 3 in which the coating has the following approximate composition in parts by weight:

ALLAN S. RICHARDSON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,319,074 McGill May 11, 1943 2,416,061 McAlevy et al. Feb. 18, 1947 

6. THE PROCESS OF COATING A TEXTILE FABRIC WHICH COMPRISES PREPARING A COMPOSITION COMPRISING AN INTIMATE MIXTURE OF 100 PARTS OF CHLOROSULFONATED ETHYLENE POLYMER AND 20 TO 40 PARTS OF POLYMERIC METHYL METHACRYLATE, DISPERSING SAID MIXTURE IN A VOLATILE SOLVENT, APPLYING SAID COMPOSITION ON A TEXTILE FABRIC HEATING TO EVAPORATE THE SOLVENT AND FURTHER HEATING TO CURE THE SAID COATING. 